US7786035B2 - Glass composition and process for producing glass composition - Google Patents

Glass composition and process for producing glass composition Download PDF

Info

Publication number
US7786035B2
US7786035B2 US11/990,355 US99035506A US7786035B2 US 7786035 B2 US7786035 B2 US 7786035B2 US 99035506 A US99035506 A US 99035506A US 7786035 B2 US7786035 B2 US 7786035B2
Authority
US
United States
Prior art keywords
glass
chloride
content
mass
glass composition
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
US11/990,355
Other languages
English (en)
Other versions
US20090131238A1 (en
Inventor
Shoichi Kishimoto
Haruki Niida
Akihiro Koyama
Yukihito Nagashima
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Avanstrate Inc
Original Assignee
Avanstrate Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Avanstrate Inc filed Critical Avanstrate Inc
Assigned to NIPPON SHEET GLASS COMPANY, LIMITED reassignment NIPPON SHEET GLASS COMPANY, LIMITED ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KISHIMOTO, SHOICHI, KOYAMA, AKIHIRO, NAGASHIMA, YUKIHITO, NIIDA, HARUKI
Assigned to AVANSTRATE INC. reassignment AVANSTRATE INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: NIPPON SHEET GLASS COMPANY, LIMITED
Publication of US20090131238A1 publication Critical patent/US20090131238A1/en
Assigned to AVANSTRATE, INC. reassignment AVANSTRATE, INC. ASSIGNEE ADDRESS CHANGE Assignors: AVANSTRATE, INC.
Application granted granted Critical
Publication of US7786035B2 publication Critical patent/US7786035B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00—Glass compositions
    • C03C3/04—Glass compositions containing silica
    • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
    • C03C3/11—Glass compositions containing silica with 40% to 90% silica, by weight containing halogen or nitrogen
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00—Glass compositions
    • C03C3/04—Glass compositions containing silica
    • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
    • C03C3/089—Glass compositions containing silica with 40% to 90% silica, by weight containing boron
    • C03C3/091—Glass compositions containing silica with 40% to 90% silica, by weight containing boron containing aluminium
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods

Definitions

  • the present invention relates to a glass composition, and a process for producing a glass composition, and particularly to alumino-borosilicate glass compositions.
  • Alkali-free borosilicate glass compositions have been used as the glass compositions for the substrate of information display devices, particularly active-matrix liquid crystal display devices.
  • a representative example of such alkali-free borosilicate glass is Code 7059 glass produced by Corning of the United States.
  • fining In manufacturing processes of glass compositions, a process that removes residual bubbles in the glass composition is generally known as fining.
  • a method of adding a fining agent to fine a glass melt is commonly known as well.
  • Arsenic oxide, antimony oxide, and fluorides are some of the known examples of the fining agent.
  • JP 10(1998)-25132A discloses a method in which sulfate and chloride are simultaneously added to raw glass materials for the purposes of melting and fining.
  • this publication teaches adding, as fining agents, sulfate in the SO 3 amount of 0.005 to 1.0 weight %, and chloride in the Cl 2 amount of 0.01 to 2.0 weight %.
  • the publication also teaches preparing sulfate and chloride as fining agents, and using BaSO 4 , CaSO 4 , and the like as the sulfate, and BaCl 2 , CaCl 2 , and the like as the chloride.
  • JP 60(1985)-141642A discloses a glass composition containing as a degassing agent at least one component selected from As 2 O 3 , Sb 2 O 3 , (NH 4 ) 2 SO 4 , NaCl, and fluorides.
  • the chloride added is an alkali earth metal chloride such as BaCl 2 , CaCl 2 .
  • the alkali-free borosilicate glass composition commonly used for the active-matrix liquid crystal display device is highly viscous and this has made fining of the glass difficult.
  • components such as aluminum, boron, and silicon have characteristics that their mobility in glass is limited by the strong electrostatic binding due to the large charge. For this reason, it has been difficult to achieve good clarity in the glass of the borosilicate glass composition.
  • JP 60(1985)-141642A teaches using NaCl.
  • a problem of using NaCl is that sodium ions dissolve out of the glass after the glass is assembled into a liquid crystal display device, and, depending on the amount of dissolved sodium ions, the performance of the liquid crystal element may be impaired.
  • an object of the invention is to provide a glass composition, usable for information display devices such as a liquid crystal display device, which contains a few bubbles and is produced using reduced amounts of highly environmentally unfriendly arsenic oxide and antimony oxide.
  • Another object of the invention is to provide a process suited for the production of such glass compositions.
  • a glass composition of the present invention includes small amounts of alkali metal oxide and Cl in an alumino-borosilicate glass composition.
  • a glass composition according to the present invention contains, in mass %, 40 to 70% SiO 2 , 5 to 20% B 2 O 3 , 10 to 25% Al 2 O 3 , 0 to 10% MgO, 0 to 20% CaO, 0 to 20% SrO, and 0 to 10% BaO, and further contains greater than 0.06% R 2 O, and greater than 0% and no greater than 1.5% Cl, where R is at least one kind selected from Li, Na, and K, and Li 2 O falls in a range of 0 to 0.5%, Na 2 O falls in a range of 0 to 1.0%, and K 2 O falls in a range of 0 to 1.5%, all in mass %.
  • the present invention provides a process for producing a glass composition.
  • the process includes a step of melting a raw glass material to obtain a glass composition.
  • the glass composition contains, in mass %, 40 to 70% SiO 2 , 5 to 20% B 2 O 3 , 10 to 25% Al 2 O 3 , 0 to 10% MgO, 0 to 20% CaO, 0 to 20% SrO, and 0 to 10% BaO and further contains greater than 0.06% R 2 O, where R is at least one kind selected from Li, Na, and K, and Li 2 O falls in a range of 0 to 0.5%, Na 2 O falls in a range of 0 to 1.0%, and K 2 O falls in a range of 0 to 1.5%, all in mass %.
  • a chloride is used as part of the raw glass material.
  • the present invention provides a glass substrate for information display devices, which consists of the glass composition. In another aspect, the present invention provides an information display device including the glass substrate for information display devices.
  • a sufficient fining effect can be obtained in an alumino-borosilicate glass composition without using, or using only a limited amount of, highly environmentally unfriendly components as represented by arsenic oxide.
  • the present invention provides ways to produce glass substrates for large information display devices readily at high yield and low cost, while avoiding use of highly environmentally unfriendly components.
  • FIG. 1 is a perspective view showing an example of a glass substrate for information display devices, formed from a glass composition of the present invention.
  • FIG. 2 is a cross sectional view of an information display device, showing an exemplary use of the glass substrate for information display devices of FIG. 1 .
  • the percentage denoting the content of each component of a glass composition and raw glass material is percent by mass.
  • a glass composition of the present invention can be produced using chloride as part of raw glass materials.
  • chlorine is contained in the glass composition by melting a batch of raw glass material that has been prepared to include chloride, particularly alkali metal chloride and/or alkali earth metal chloride. In this way, chlorine effectively can exhibit its fining effect in the glass melt.
  • the chloride is preferably at least one compound selected from, for example, magnesium chloride, calcium chloride, strontium chloride, barium chloride, lithium chloride, sodium chloride, and potassium chloride, more preferably lithium chloride, sodium chloride, and potassium chloride, and even more preferably potassium chloride.
  • the chloride also may be at least one compound selected from magnesium chloride, calcium chloride, strontium chloride, and barium chloride.
  • the chloride content in a raw glass material is desirably in a range of greater than 0% to no greater than 1.5%, preferably 0.05 to 1.5%, and more preferably greater than 0.09% to no greater than 1.5%. In this way, chlorine effectively can exhibit its fining effect in the glass melt.
  • the boiling point of chloride, particularly alkali metal chloride is near the temperature range of, for example, 1400° C. to 1650° C. suited for the melting of a glass composition of the present invention.
  • LiCl has a boiling point in a range of 1325° C. to 1360° C.
  • NaCl has a boiling point of 1413° C.
  • KCl sublimes at 1500° C. That is, in a suitable melting temperature range of a glass composition of the present invention, the vapor pressures of these alkali metal chlorides are considered to increase to levels comparable to atmospheric pressure.
  • the chlorine would bind to the alkali in the glass melt and generate an alkali metal chloride gas.
  • the alkali metal chloride gas forms bubbles in the glass melt, or increases the size of bubbles in the glass melt. These bubbles would then float to the surface of the glass melt and burst, with the result that the bubbles are removed from the glass melt. It is considered that the fining of the glass composition proceeds due to this mechanism.
  • KCl is a monovalent salt and therefore is subject to weak electric binding in the molten glass.
  • potassium has a greater ion radius than sodium, its mobility is limited by the steric hinderance in the dense structure of the glass composition that has undergone volume shrinkage as a result of cooling from the molten state.
  • KCl vaporizes at higher temperatures compared with NaCl. That is, KCl vaporizes in a temperature range where the glass has low viscosity. Generally, this makes use of KCl particularly advantageous for the fining of high-viscosity glass.
  • a fining vessel that has a complex structure for sealing or other purposes.
  • fining should be performed preferably in a lower temperature range (1450° C. to 1500° C.) than normal fining temperatures (1600° C. or greater).
  • the use of KCl is particularly advantageous for vacuum fining, because KCl is more weakly bound by charges than alkali earth metal chloride and therefore moves more freely in high-viscosity molten glass.
  • Alkali metal oxides such as Li 2 O, Na 2 O, and K 2 O dissolve out of the glass and adversely affect other members. For this reason, alkali metal oxides have been excluded from the glass composition in applications as the glass substrate for liquid crystal display devices. However, when the alkali metal oxides are used in trace amounts, the glass fining effect can be improved while suppressing the influence of dissolution from the glass at a level that would not cause any practical problem. This is because the alkali metal oxides lower the viscosity of the glass and contribute to facilitating decomposition of silica, which does not easily decompose in the raw glass material.
  • the K 2 O content in the glass composition be adjusted to be at least equal to the Na 2 O content, more preferably sufficiently greater than the Na 2 O content, or more specifically at least two times, more preferably at least three times, and even more preferably at least four times the Na 2 O content.
  • the Li 2 O content it is preferable to adjust the Li 2 O content to be less than the Na 2 O content, and more preferably less than half of the Na 2 O content.
  • the glass composition contains two or more kinds of alkali metal oxides.
  • the mobility rate of the alkali metal ions can be reduced more effectively by the combined alkaline effect. This further reduces the dissolution of the alkali metals or alkali metal ions from the glass composition, thereby enhancing the chemical durability of the glass composition.
  • SiO 2 is an essential component as a glass network former, and it has the effect of enhancing chemical durability and heat resistance of the glass. This effect cannot be obtained sufficiently when the SiO 2 content is less than 40%.
  • the SiO 2 content exceeds 70%, the glass readily undergoes devitrification. This makes it difficult to mold the glass, and the increased viscosity makes it difficult to homogenize the glass. Therefore, the SiO 2 content should be 40 to 70%, preferably 58 to 70%, 57 to 65%, 60 to 65%, 56 to 65%, and 56 to 60%.
  • B 2 O 3 is an essential component that lowers the viscosity of the glass and facilitates decomposition and fining of the glass. This effect cannot be obtained sufficiently when the B 2 O 3 content is less than 5%.
  • B 2 O 3 content exceeds 20%, acid resistance of the glass deteriorates and vaporization occurs rapidly, which makes it difficult to homogenize the glass. Therefore, B 2 O 3 content should be 5 to 20%, preferably 8 to 13%, and 5 to 12%.
  • Al 2 O 3 is an essential component as a glass network former, and it has the effect of enhancing chemical durability and heat resistance of the glass. This effect cannot be obtained sufficiently when the Al 2 O 3 content is less than 5%. When the Al 2 O 3 content exceeds 25%, viscosity of the glass lowers and acid resistance deteriorates. Therefore, Al 2 O 3 content should be 10 to 25%, preferably 13 to 20%, 10 to 20%, and 10 to 18%.
  • MgO and CaO are optional components that lower viscosity of the glass and facilitate decomposition and fining of the glass.
  • the MgO content and the CaO content exceed 10% and 20%, respectively, the chemical durability of the glass deteriorates. Therefore, the MgO content should be 0 to 10%, and the CaO content should be 0 to 20%.
  • both MgO and CaO preferably should be contained in the amount of at least 1%.
  • the MgO content may be 5 to 10%.
  • the MgO content preferably should be no greater than 5% and the CaO content preferably should be no greater than 10%.
  • the MgO content is more preferably 1 to 5%, and the CaO content is more preferably 1 to 10%. Even more preferably, the CaO content is 1 to 6%, and the MgO content is less than 5%.
  • SrO and BaO are optional components that lower viscosity of the glass and facilitate decomposition and fining of the glass.
  • the SrO content and the BaO content exceed 20% and 10%, respectively, the chemical durability of the glass deteriorates. Further, because of large ion radii, there are cases where SrO and BaO hinder mobility of potassium and chloride ions in the glass, which makes it difficult to fine the glass. Therefore, the SrO content should be 0 to 20%, preferably 0 to 4%, more preferably 1 to 10%, and even more preferably 1 to 6%.
  • the BaO content should be 0 to 10%, more preferably 0 to 1%.
  • the BaO content may be 3 to 10%.
  • K 2 O is a component that lowers glass viscosity and facilitates fining of the glass.
  • K 2 O binds to the chlorine ions in the glass melt and vaporizes in the form of potassium chloride at temperatures of 1500° C. or greater. This facilitates increasing the size of bubbles in the glass and causes the bubbles to float to the surface.
  • K 2 O also serves to homogenize the glass melt.
  • the K 2 O content may be 0%. However, the K 2 O content preferably should be 0.05% or greater, more preferably 0.07% or greater. Meanwhile, there are cases where K 2 O increases the thermal expansion coefficient of the glass. In order to prevent a difference in the thermal expansion coefficient from silicone materials, the K 2 O content is desirably no greater than 1.5%. That is, the K 2 O content may be 0.05 to 1.5%.
  • K 2 O Unlike other alkali metal oxides such as Na 2 O and Li 2 O, K 2 O has a small mobility rate in glass and does not easily dissolve out of the glass. This allows the K 2 O to be contained in the glass substrate for information display devices such as a liquid crystal display device.
  • the Na 2 O content is desirably no greater than the K 2 O content, as described above.
  • the Na 2 O content is 0 to 1.0%, preferably 0 to 0.5%, and more preferably 0 to 0.1%.
  • Li 2 O is an optional component that lowers glass viscosity and facilitates fining of the glass.
  • Li 2 O vaporizes in the form of lithium chloride and increases the size of bubbles in the glass and causes the bubbles to float to the surface.
  • Li 2 O also serves to homogenize the glass melt.
  • the Li 2 O content is 0 to 0.5%, preferably no greater than 0.07%. That is, the Li 2 O content may be 0.015 to 0.5%.
  • the Cl content may be in a range exceeding 0%. However, because Cl is a component that can facilitate fining of the glass, the Cl content is preferably 0.04% or greater, more preferably greater than 0.09%. The mechanism of fining the glass by Cl is as given above.
  • Cl is volatile, the Cl content is often greater in the raw glass material than in the product glass. For this reason, a raw glass material batch should contain Cl in the amount of 0.05% or greater. However, since Cl does not readily decompose into the glass, condensation may occur in the glass being formed when the Cl content exceeds 1.5%. This may lead to formation of bubbles containing chloride crystals, or may encourage phase separation or devitrification of the glass. It is therefore desirable that the Cl content be no greater than 1.5%.
  • the potassium as the constituting element of K 2 O, and Cl may be supplied from different source materials. However, the absolute fractions of these elements are so small that they compete with other ions for the binding reaction, with the result that the binding of these elements may not proceed sufficiently.
  • K and Cl can exist as KCl from an early stage of melting. This is advantageous for the fining because bubbles are formed rapidly when the glass temperature exceeds the boiling point of KCl. It is therefore preferable that KCl be used as the source material of K and Cl.
  • the total content of alkali metal oxides (for example, the R 2 O content representing the total content of Li 2 O, Na 2 O, and K 2 O) is desirably in a range of greater than 0.06% to no greater than 1.5%, preferably greater than 0.07% and no greater than 1.5%.
  • the R 2 O content may be in a range exceeding 0.2%.
  • Li 2 O, Na 2 O, and K 2 O are all alkali metal oxides and therefore the cations move more freely in the glass than other metal cations.
  • K 2 O has the slowest mobility rate in glass.
  • chemical durability of the glass composition can be improved, as described above.
  • a superior fining effect can be obtained as compared with adding only one kind of alkali metal oxide. Such a superior fining effect will be even more prominent when K 2 O and Li 2 O are used together.
  • a glass composition of the present invention may contain any of the foregoing glass components in the defined ranges, and, essentially, preferably only the foregoing glass components are contained in the defined ranges.
  • other components also may be contained for the purposes of controlling refractive index and temperature viscosity characteristics and preventing devitrification, for example.
  • ZnO, SnO 2 , TiO 2 , Y 2 O 3 , La 2 O 3 , Ta 2 O 5 , Nb 2 O 5 , GeO 2 , or Ga 2 O 5 may be contained in the total amount of at most 3%. In certain cases, addition of ZnO may not be preferable. Further, oxides of As or Sb may be contained, as will be described later.
  • Fe 2 O 3 also may be contained in a range of less than 0.5%.
  • NiO may be contained in a range of less than 0.05%.
  • CoO may be contained in a range of less than 0.01%.
  • Mo may be contained in a range of less than 0.02%.
  • the glass composition may be a composition that essentially comprises the foregoing component groups (a group of components SiO 2 to Cl individually described above, and a group of components ZnO to Mo given in the foregoing paragraph). In this case, the glass composition does not essentially include components other than these component groups.
  • the language “does not essentially include” is intended to encompass inclusion of a trace amount of impurity that is inevitable in industrial manufacturing. Specifically, it is intended that a trace amount of impurity is contained in the amount of less than 0.05%, preferably less than 0.03%, and more preferably less than 0.01%.
  • a glass composition of the present invention With a glass composition of the present invention, the amount of arsenic oxide or antimony oxide used can be reduced while at the same time realizing desirable glass clarity.
  • the present invention should not be understood to completely exclude As, Sb, or other highly environmentally unfriendly components.
  • a glass composition of the present invention does not essentially contain oxides of arsenic and antimony, the present invention is not limited to this.
  • a glass composition of the present invention may include oxides of arsenic and/or antimony.
  • oxides of arsenic may be contained in the As 2 O 3 amount of greater than 0% to no greater than 0.1%.
  • Oxides of antimony, not as environmentally unfriendly as arsenic may be contained in the Sb 2 O 3 amount of greater than 0% to less than 0.4%, as will be described later in Examples.
  • the content of each component SiO 2 to BaO in the foregoing component group may be, for example, 58 to 70% SiO 2 , 8 to 13% B 2 O 3 , 13 to 20% Al 2 O 3 , 1 to 5% MgO, 1 to 10% CaO, 0 to 4% SrO, and 0 to 1% BaO.
  • the content may be, for example, 57 to 65% SiO 2 , 5 to 12% B 2 O 3 , 10 to 20% Al 2 O 3 , 5 to 10% MgO, 0 to 10% CaO, and 0 to 10% SrO.
  • the content may be, for example, 60 to 65% SiO 2 , 5 to 12% (preferably 9 to 12%) B 2 O 3 , 10 to 20% (preferably 10 to 15%) Al 2 O 3 , 0 to 5% (preferably 1 to 5%, more preferably 2 to 4.5%) MgO, 1 to 6% CaO, 0 to 10% SrO, and 0 to 1% BaO.
  • the content may be, for example, 56 to 65% SiO 2 , 5 to 12% B 2 O 3 , 10 to 18% Al 2 O 3 , 0 to 5% (preferably 2 to 5%) MgO, 1 to 10% CaO, 1 to 10% (preferably, 3 to 10%) SrO, and 0 to 1% BaO.
  • the content may be, for example, 56 to 60% SiO 2 , 5 to 12% B 2 O 3 , 10 to 18% Al 2 O 3 , 0 to 5% MgO, 1 to 6% CaO, 1 to 6% SrO, and 3 to 10% BaO.
  • the content may be, for example, 58 to 64% SiO 2 , 8 to 12% B 2 O 3 , 5 to 18% (preferably, 15 to 18%) Al 2 O 3 , 1 to 10% (preferably 1 to 5%, more preferably 1 to 2%) MgO, 1 to 6% (preferably 3 to 8%) CaO, 1.5 to 4.5% (preferably 2 to 4%) SrO, and 1 to 5% (preferably 1 to 4%) BaO.
  • a method for forming a glass composition of the present invention is not particularly limited.
  • the downdraw process or fusion process may be used.
  • a glass composition of the present invention can be used suitably as a glass substrate 10 for large and thin information display devices such as a liquid crystal display device and a plasma display panel, as shown in FIG. 1 .
  • the glass substrate 10 may be used, for example, as a front panel 11 and a back panel 12 of a liquid crystal display device 100 , illustrated in FIG. 2 as an example of an information display device.
  • the front panel 11 and the back panel 12 provided for the liquid crystal display device 100 are disposed on the both sides of a liquid crystal layer 20 with a sealant 30 in between, together with other members such as transparent electrodes 40 and alignment films 50 .
  • batches of raw glass materials (may be referred to as “batches” hereinafter) shown in Table 1A and Table 1B were prepared.
  • common raw glass materials silica, boric anhydride, alumina, basic magnesium carbonate, calcium carbonate, strontium carbonate, and barium carbonate were used.
  • Cl sources potassium chloride, calcium chloride, sodium chloride, lithium chloride, and the like were used.
  • Each batch was melted and fined in a platinum crucible.
  • the crucible was placed in an electric furnace that had been set at 1600° C., and maintained therein for 16 hours to melt the batch.
  • the crucible with the glass melt was taken out of the furnace and allowed to cool and solidify at room temperature.
  • a glass body was obtained.
  • the glass body was taken out of the crucible and gradually cooled.
  • the cooling was performed according to the following procedure.
  • the glass body was placed in a separate electric furnace that had been set at 700° C., and maintained therein for 30 minutes.
  • the glass body was then allowed to cool to room temperature by turning off the electric furnace.
  • the resulting glass body was used as a sample glass.
  • the sample glass was comminuted to quantify the glass composition by fluorescent x-ray analysis using RIX3001 from Rigaku Corporation. Note that, boron (B) was quantified by emission spectral analysis using ICPS-10001V of Shimadzu Corporation.
  • the clarity of the glass body was evaluated through observation of the sample glass with an optical microscope (40 ⁇ ) and by finding the number of bubbles per 1 cm 3 of glass from thickness, view area, and the number of bubbles observed.
  • Clarity bubble conditions
  • Clarity was denoted as “Excellent” when the relative ratio of the bubble count observed in Examples was less than 0.5, “Good” when 0.5 or greater and less than 1.0, and “Poor” when 1.0 or greater.
  • sample glasses of Examples 1 to 6 were compared with the bubble conditions of Comparative Examples 1 and 2.
  • sample glasses of Examples 7 to 12 were compared with the bubble conditions of Comparative Example 3.
  • a thermal expansion coefficient and a glass transition point were measured by raising the temperature at a rate of 5° C./min, using a differential dilatometer (Thermoflex TMA8140, Rigaku Corporation).
  • the sample glasses of Examples 1 to 12 had the compositions shown in Table 2A and Table 2B.
  • the number of residual bubbles in the sample glasses of Examples 1 to 12 was considerably fewer than that in the Comparative Examples. Further, the sample glasses of Examples 1 to 12 are free from arsenic oxide or other environmentally highly unfriendly fining agents. Taken together, the present invention enables manufacture of glass substrates that have very few defects due to bubbles or other deficiencies, without using, or using a reduced amount of, arsenic oxide and the like.
  • the sample glass of Comparative Example 1 has the composition shown in Table 2A. This glass body was fined using CaCl 2 as the Cl source and does not contain R 2 O. The sample glass of Comparative Example 1 had large numbers of residual bubbles, which accounted for poor clarity.
  • the sample glasses of Comparative Examples 2 and 3 have the compositions shown in Table 2A and Table 2B, respectively. These glass bodies were formed without using chlorides of alkali metals and do not contain Cl and R 2 O. The sample glasses of Comparative Examples 2 and 3 had considerably large numbers of residual bubbles, which accounted for very poor clarity.
  • Example 13 to 21 and Comparative Examples 4 to 6 suitable composition ranges of the glass composition were confirmed.
  • the glass compositions were evaluated comprehensively by considering various factors together, such as Glass transition point, thermal expansion coefficient, and bubble conditions, taking into consideration applications as a glass substrate for information display devices.
  • Measurement of devitrification temperature was performed as follows. First, the sample glass was comminuted with a mortar. Then, glass particles that passed a 2380 ⁇ m mesh sieve but did not pass a 1000 ⁇ m mesh sieve were collected from the comminuted sample glasses (glass particles). The glass particles so collected were subjected to ultrasonic washing in ethanol and dried to prepare a measurement sample. The measurement sample (25 g) was placed on a platinum board (12 mm in width, 200 mm in length) and put in a temperature gradient furnace where the measurement sample was held for 2 hours. The glass was taken out of the furnace and crystals that grew in the glass (devitrification) were observed with an optical microscope. A maximum temperature at which crystals were observed was given as a devitrification temperature.
  • Example 4 Example 5
  • Example 6 Composition SiO 2 60.1 59.8 54.7 49.8 71.4 [mass %] B 2 O 3 8.0 6.9 9.9 23.9 4.0 Al 2 O 3 17.9 12.9 14.9 9.0 10.9 MgO 1.0 8.0 14.9 5.0 3.9 CaO 7.9 3.0 4.9 4.0 3.0 SrO 1.5 8.9 — 3.9 3.1 BaO 3.0 — — 4.0 3.1 Li 2 O 0.03 0.04 0.03 0.03 0.03 Na 2 O 0.04 0.09 0.04 0.04 0.04 K 2 O 0.35 0.37 0.39 0.36 0.37 Cl 0.15 0.16 0.17 0.15 0.16 Glass transition point [° C.] 718 687 — — 718 Thermal expansion 37 44 — — 30 coefficient [ ⁇ 10 ⁇ 7 /° C.] Devitrification ⁇ 895 — — — — temperature [° C.] Bubble condition Good Excellent — — Poor Overall evaluation Excellent Good Poor Poor Poor Poor Poor Poor Poor
  • the sample glasses of Examples 13 to 21 and Comparative Examples 4 to 6 had compositions shown in Table 4. As shown in Table 4, the number of residual bubbles in the sample glasses of Examples 13 to 21 was considerably smaller than that in Comparative Example 6.
  • the sample glasses of Examples 13 to 21 did not contain arsenic oxide or other highly environmentally unfriendly fining agents.
  • the devitrification temperature was 1027° C. or less, for example, in the sample glasses of Examples 13 to 20, and less than 900° C. in the sample glasses of Examples 17 to 20. This gave an excellent mark for Examples 13 to 20 in the overall evaluation.
  • the glass compositions may include small amounts of As 2 O 5 or Sb 2 O 3 .
  • the sample glasses of Examples 22 to 24 and Comparative Example 7 had the compositions shown in Table 6. As shown in Table 6, the number of residual bubbles in the sample glasses of Examples 22 to 24 was considerably smaller than that in Comparative Example 7.
  • the present invention readily enables manufacture of glass substrates that have very few defects due to bubbles or other deficiencies, without using, or using a reduced amount of, arsenic oxide and the like.
  • the present invention provides glass compositions that are applicable to uses requiring chemical resistance, heat resistance, and a small thermal expansion coefficient.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Mathematical Physics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Optics & Photonics (AREA)
  • Glass Compositions (AREA)
  • Glass Melting And Manufacturing (AREA)
  • Liquid Crystal (AREA)
  • Devices For Indicating Variable Information By Combining Individual Elements (AREA)
US11/990,355 2005-08-15 2006-08-04 Glass composition and process for producing glass composition Active US7786035B2 (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP2005235568 2005-08-15
JP2005235569 2005-08-15
JP2005-235568 2005-08-15
JP2005-235569 2005-08-15
PCT/JP2006/315535 WO2007020824A1 (ja) 2005-08-15 2006-08-04 ガラス組成物およびガラス組成物の製造方法

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2006/315535 A-371-Of-International WO2007020824A1 (ja) 2005-08-15 2006-08-04 ガラス組成物およびガラス組成物の製造方法

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US12/834,486 Continuation US8129299B2 (en) 2005-08-15 2010-07-12 Glass composition and process for producing glass composition

Publications (2)

Publication Number Publication Date
US20090131238A1 US20090131238A1 (en) 2009-05-21
US7786035B2 true US7786035B2 (en) 2010-08-31

Family

ID=37757486

Family Applications (3)

Application Number Title Priority Date Filing Date
US11/990,355 Active US7786035B2 (en) 2005-08-15 2006-08-04 Glass composition and process for producing glass composition
US12/834,486 Active US8129299B2 (en) 2005-08-15 2010-07-12 Glass composition and process for producing glass composition
US13/362,852 Abandoned US20120129679A1 (en) 2005-08-15 2012-01-31 Glass composition and process for producing glass composition

Family Applications After (2)

Application Number Title Priority Date Filing Date
US12/834,486 Active US8129299B2 (en) 2005-08-15 2010-07-12 Glass composition and process for producing glass composition
US13/362,852 Abandoned US20120129679A1 (en) 2005-08-15 2012-01-31 Glass composition and process for producing glass composition

Country Status (8)

Country Link
US (3) US7786035B2 (ko)
JP (5) JPWO2007020824A1 (ko)
KR (2) KR101297031B1 (ko)
CN (2) CN104250066A (ko)
DE (2) DE112006004278A5 (ko)
SG (1) SG169374A1 (ko)
TW (3) TWI402236B (ko)
WO (1) WO2007020824A1 (ko)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110207594A1 (en) * 2005-08-15 2011-08-25 Avanstrate Inc. Glass composition
US20110318561A1 (en) * 2009-03-19 2011-12-29 Takashi Murata Alkali-free glass
US20120095149A1 (en) * 2008-04-28 2012-04-19 Kaori Sawanoi Glass composition for glass fiber, glass fiber, and glass fiber sheet
US20130244858A1 (en) * 2011-09-09 2013-09-19 Hong Li Glass Compositions And Fibers Made Therefrom
US11214512B2 (en) 2017-12-19 2022-01-04 Owens Coming Intellectual Capital, LLC High performance fiberglass composition

Families Citing this family (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7593154B2 (en) * 2005-10-11 2009-09-22 Sage Electrochromics, Inc. Electrochromic devices having improved ion conducting layers
US9394196B2 (en) 2006-12-14 2016-07-19 Ppg Industries Ohio, Inc. Low density and high strength fiber glass for reinforcement applications
US9056786B2 (en) 2006-12-14 2015-06-16 Ppg Industries Ohio, Inc. Low density and high strength fiber glass for ballistic applications
US7829490B2 (en) * 2006-12-14 2010-11-09 Ppg Industries Ohio, Inc. Low dielectric glass and fiber glass for electronic applications
US8697591B2 (en) * 2006-12-14 2014-04-15 Ppg Industries Ohio, Inc. Low dielectric glass and fiber glass
US9156728B2 (en) 2006-12-14 2015-10-13 Ppg Industries Ohio, Inc. Low density and high strength fiber glass for ballistic applications
JP5483821B2 (ja) 2007-02-27 2014-05-07 ＡｖａｎＳｔｒａｔｅ株式会社 表示装置用ガラス基板および表示装置
US8445394B2 (en) * 2008-10-06 2013-05-21 Corning Incorporated Intermediate thermal expansion coefficient glass
FR2948356B1 (fr) * 2009-07-22 2011-08-19 Saint Gobain Dispositif electrochrome
JP5537144B2 (ja) 2009-12-16 2014-07-02 ＡｖａｎＳｔｒａｔｅ株式会社 ガラス組成物とそれを用いたフラットパネルディスプレイ用ガラス基板
US9029280B2 (en) * 2011-07-01 2015-05-12 Avanstrate Inc. Glass substrate for flat panel display and method for manufacturing same
US9162919B2 (en) * 2012-02-28 2015-10-20 Corning Incorporated High strain point aluminosilicate glasses
JP5862952B2 (ja) * 2012-05-24 2016-02-16 日本電気硝子株式会社 ホウ珪酸ガラスの製造方法
JP5914453B2 (ja) * 2012-12-28 2016-05-11 ＡｖａｎＳｔｒａｔｅ株式会社 ディスプレイ用ガラス基板およびその製造方法
EP3033310B1 (en) 2013-08-15 2021-03-10 Corning Incorporated Alkali-doped and alkali-free boroaluminosilicate glass
CN105980147B (zh) 2013-08-15 2020-07-24 康宁公司 中至高cte玻璃以及包含其的玻璃制品
WO2016063981A1 (ja) 2014-10-23 2016-04-28 旭硝子株式会社 無アルカリガラス
CN106746601B (zh) 2016-12-30 2019-06-04 东旭集团有限公司 用于制备玻璃的组合物、玻璃制品及用途
CN107935385A (zh) * 2017-11-30 2018-04-20 滕州市耀海玻雕有限公司 一种隔热型复合防火玻璃及其制备方法
JP2021008374A (ja) * 2019-07-01 2021-01-28 日本電気硝子株式会社 ガラス基板
JP7409636B2 (ja) * 2019-11-27 2024-01-09 株式会社住田光学ガラス 多成分系酸化物ガラス、光学素子、光ファイバ、及び多成分系酸化物ガラスの製造方法
JPWO2021241312A1 (ko) * 2020-05-28 2021-12-02
CN114477762B (zh) * 2021-12-24 2024-03-15 中建材玻璃新材料研究院集团有限公司 一种无硼铝硅酸盐玻璃
CN117923792A (zh) * 2023-12-18 2024-04-26 彩虹显示器件股份有限公司 一种低润湿角玻璃基板、制备方法及显示面板

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60141642A (ja) 1983-12-28 1985-07-26 Tdk Corp 高温度安定低膨脹ガラス
JPH1025132A (ja) 1996-07-09 1998-01-27 Nippon Electric Glass Co Ltd 無アルカリガラス及びその製造方法
JPH10120437A (ja) * 1996-10-16 1998-05-12 Nitto Boseki Co Ltd 低誘電率ガラス繊維
JP2000128572A (ja) 1998-10-26 2000-05-09 Nippon Electric Glass Co Ltd 硼珪酸ガラス及びその製造方法
JP2002201040A (ja) 2000-10-31 2002-07-16 Asahi Glass Co Ltd アルミノホウケイ酸ガラス
JP2003026442A (ja) 2001-07-13 2003-01-29 Nippon Electric Glass Co Ltd 電界放射型ディスプレイ用ガラス基板
US20030121288A1 (en) 1996-08-21 2003-07-03 Nippon Electric Glass Co., Ltd. Alkali-free glass and method for producing the same
US6680266B1 (en) * 1999-09-04 2004-01-20 Schott Glas Alkaline-earth aluminoborosilicate glass and the uses thereof
US6777359B2 (en) * 2001-09-21 2004-08-17 Hoya Corporation Polarizing glass and preparation method thereof
JP2005089259A (ja) 2003-09-18 2005-04-07 Nippon Electric Glass Co Ltd ガラス基板
US20050209084A1 (en) 2004-03-22 2005-09-22 Tatsuya Takaya Glass for display substrate
WO2006064878A1 (ja) 2004-12-16 2006-06-22 Nippon Sheet Glass Company, Limited ガラス組成物およびその製造方法
US20080206494A1 (en) * 2007-02-27 2008-08-28 Nh Techno Glass Corporation Glass substrate for display and display
US20090143214A1 (en) * 2005-08-15 2009-06-04 Nippon Sheet Glass Company, Limited Glass composition

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US32117A (en) 1861-04-23 Improvement in seed-planters
US4074989A (en) * 1976-11-08 1978-02-21 Ppg Industries, Inc. Method of preparing anhydrous boric acid-containing glass batch
FR2678604B1 (fr) * 1991-07-02 1993-11-12 Saint Gobain Vitrage Internal Composition de verre trouvant application dans le domaine de l'electronique.
JP3741526B2 (ja) * 1997-09-30 2006-02-01 セントラル硝子株式会社 ディスプレイ装置用基板ガラス
JPH11180727A (ja) * 1997-12-22 1999-07-06 Central Glass Co Ltd 表示装置用基板ガラス組成物
JPH11180728A (ja) * 1997-12-22 1999-07-06 Central Glass Co Ltd ディスプレイ装置用基板ガラス組成物
JPH11310433A (ja) * 1998-04-27 1999-11-09 Central Glass Co Ltd 表示装置用基板ガラス
JP2000143280A (ja) * 1998-11-09 2000-05-23 Central Glass Co Ltd ソーダ石灰シリカ系ガラス
JP2000169180A (ja) * 1998-11-30 2000-06-20 Asahi Glass Co Ltd ディスプレイ基板用フロートガラス
JP4158249B2 (ja) * 1998-11-30 2008-10-01 旭硝子株式会社 ディスプレイ基板用ガラスをフロート法によって製造する方法
JP2000357477A (ja) * 1999-06-15 2000-12-26 Nippon Sheet Glass Co Ltd ディスプレイ用ガラス成形品及びガラス容器
DE10000836B4 (de) * 2000-01-12 2005-03-17 Schott Ag Alkalifreies Aluminoborosilicatglas und dessen Verwendungen
JP4017466B2 (ja) * 2001-12-04 2007-12-05 岡本硝子株式会社 耐熱性ガラス
JP2003238174A (ja) * 2002-02-15 2003-08-27 Asahi Glass Co Ltd フロートガラスの製造方法
JP2005053708A (ja) * 2003-08-04 2005-03-03 Nippon Electric Glass Co Ltd フラットパネルディスプレイ用ガラス
JP4400362B2 (ja) * 2003-08-08 2010-01-20 日本電気硝子株式会社 外部電極蛍光ランプ用外套容器
JP4378152B2 (ja) * 2003-11-07 2009-12-02 岡本硝子株式会社 耐熱性ガラス
JP4715258B2 (ja) * 2005-03-22 2011-07-06 旭硝子株式会社 ガラスおよびガラス製造方法

Patent Citations (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60141642A (ja) 1983-12-28 1985-07-26 Tdk Corp 高温度安定低膨脹ガラス
JPH1025132A (ja) 1996-07-09 1998-01-27 Nippon Electric Glass Co Ltd 無アルカリガラス及びその製造方法
US20030121288A1 (en) 1996-08-21 2003-07-03 Nippon Electric Glass Co., Ltd. Alkali-free glass and method for producing the same
JPH10120437A (ja) * 1996-10-16 1998-05-12 Nitto Boseki Co Ltd 低誘電率ガラス繊維
JP2000128572A (ja) 1998-10-26 2000-05-09 Nippon Electric Glass Co Ltd 硼珪酸ガラス及びその製造方法
US6680266B1 (en) * 1999-09-04 2004-01-20 Schott Glas Alkaline-earth aluminoborosilicate glass and the uses thereof
JP2002201040A (ja) 2000-10-31 2002-07-16 Asahi Glass Co Ltd アルミノホウケイ酸ガラス
JP2003026442A (ja) 2001-07-13 2003-01-29 Nippon Electric Glass Co Ltd 電界放射型ディスプレイ用ガラス基板
US6777359B2 (en) * 2001-09-21 2004-08-17 Hoya Corporation Polarizing glass and preparation method thereof
JP2005089259A (ja) 2003-09-18 2005-04-07 Nippon Electric Glass Co Ltd ガラス基板
US20050209084A1 (en) 2004-03-22 2005-09-22 Tatsuya Takaya Glass for display substrate
JP2005306719A (ja) 2004-03-22 2005-11-04 Nippon Electric Glass Co Ltd ディスプレイ基板用ガラス
WO2006064878A1 (ja) 2004-12-16 2006-06-22 Nippon Sheet Glass Company, Limited ガラス組成物およびその製造方法
US20080090717A1 (en) 2004-12-16 2008-04-17 Nippon Sheet Glass Company, Limited Glass Composition And Process For Producing The Same
US20090143214A1 (en) * 2005-08-15 2009-06-04 Nippon Sheet Glass Company, Limited Glass composition
US20080206494A1 (en) * 2007-02-27 2008-08-28 Nh Techno Glass Corporation Glass substrate for display and display

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
English translation of International Preliminary Report on Patentability and Written Opinion of the International Searching Authority, dated Feb. 20, 2008.

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110207594A1 (en) * 2005-08-15 2011-08-25 Avanstrate Inc. Glass composition
US8399370B2 (en) * 2005-08-15 2013-03-19 Avanstrate Inc. Glass composition
US20120095149A1 (en) * 2008-04-28 2012-04-19 Kaori Sawanoi Glass composition for glass fiber, glass fiber, and glass fiber sheet
US8679993B2 (en) * 2008-04-28 2014-03-25 Nippon Electric Glass Co., Ltd. Glass composition for glass fiber, glass fiber, and glass fiber sheet
US20110318561A1 (en) * 2009-03-19 2011-12-29 Takashi Murata Alkali-free glass
US8835335B2 (en) * 2009-03-19 2014-09-16 Nippon Electric Glass Co., Ltd. Alkali-free glass
US20130244858A1 (en) * 2011-09-09 2013-09-19 Hong Li Glass Compositions And Fibers Made Therefrom
US8901020B2 (en) * 2011-09-09 2014-12-02 Ppg Industries Ohio, Inc. Glass compositions and fibers made therefrom
US9714189B2 (en) 2011-09-09 2017-07-25 Ppg Industries Ohio, Inc. Glass compositions and fibers made therefrom
US10843959B2 (en) 2011-09-09 2020-11-24 Electric Glass Fiber America, LLC Glass compositions and fibers made therefrom
US11214512B2 (en) 2017-12-19 2022-01-04 Owens Coming Intellectual Capital, LLC High performance fiberglass composition

Also Published As

Publication number Publication date
DE112006002185B4 (de) 2017-03-23
JPWO2007020824A1 (ja) 2009-02-26
TW201446697A (zh) 2014-12-16
JP5719806B2 (ja) 2015-05-20
JP5719810B2 (ja) 2015-05-20
DE112006004278A5 (de) 2015-01-15
TW200710056A (en) 2007-03-16
TWI547460B (zh) 2016-09-01
DE112006002185B9 (de) 2017-06-29
JP5719805B2 (ja) 2015-05-20
CN104250066A (zh) 2014-12-31
US20120129679A1 (en) 2012-05-24
WO2007020824A1 (ja) 2007-02-22
DE112006002185T5 (de) 2008-06-26
US8129299B2 (en) 2012-03-06
JP2012188350A (ja) 2012-10-04
KR101266223B1 (ko) 2013-05-21
KR101297031B1 (ko) 2013-08-14
TWI402236B (zh) 2013-07-21
TW201336798A (zh) 2013-09-16
JP2012254926A (ja) 2012-12-27
TWI561487B (ko) 2016-12-11
JP2012180279A (ja) 2012-09-20
KR20120125648A (ko) 2012-11-16
JP5685568B2 (ja) 2015-03-18
CN104261675A (zh) 2015-01-07
KR20080033517A (ko) 2008-04-16
SG169374A1 (en) 2011-03-30
US20100273634A1 (en) 2010-10-28
JP2013040098A (ja) 2013-02-28
US20090131238A1 (en) 2009-05-21

Similar Documents

Publication Publication Date Title
US7786035B2 (en) Glass composition and process for producing glass composition
US7960301B2 (en) Glass composition
US20080090717A1 (en) Glass Composition And Process For Producing The Same
JP3460298B2 (ja) 基板用ガラス組成物
CN101243020A (zh) 玻璃组合物以及玻璃组合物的制造方法

Legal Events

Date Code Title Description
AS Assignment

Owner name: NIPPON SHEET GLASS COMPANY, LIMITED, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KISHIMOTO, SHOICHI;NIIDA, HARUKI;KOYAMA, AKIHIRO;AND OTHERS;REEL/FRAME:021181/0857;SIGNING DATES FROM 20080129 TO 20080205

Owner name: NIPPON SHEET GLASS COMPANY, LIMITED, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KISHIMOTO, SHOICHI;NIIDA, HARUKI;KOYAMA, AKIHIRO;AND OTHERS;SIGNING DATES FROM 20080129 TO 20080205;REEL/FRAME:021181/0857

AS Assignment

Owner name: AVANSTRATE INC., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NIPPON SHEET GLASS COMPANY, LIMITED;REEL/FRAME:022489/0321

Effective date: 20090302

AS Assignment

Owner name: AVANSTRATE, INC., JAPAN

Free format text: ASSIGNEE ADDRESS CHANGE;ASSIGNOR:AVANSTRATE, INC.;REEL/FRAME:024636/0942

Effective date: 20100701

STCF Information on status: patent grant

Free format text: PATENTED CASE

CC Certificate of correction
FPAY Fee payment

Year of fee payment: 4

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552)

Year of fee payment: 8

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 12TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1553); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 12